[turbofan] First steps towards optimizing for-in loops.

src/compiler/js-graph.h

 // Copyright 2014 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_COMPILER_JS_GRAPH_H_
 #define V8_COMPILER_JS_GRAPH_H_
 
 #include "src/compiler/common-node-cache.h"
 #include "src/compiler/common-operator.h"
 #include "src/compiler/graph.h"
@@ skipping 84 matching lines @@
   }
 
   // Creates a Float32Constant node, usually canonicalized.
   Node* Float32Constant(float value);
 
   // Creates a Float64Constant node, usually canonicalized.
   Node* Float64Constant(double value);
 
   // Creates an ExternalConstant node, usually canonicalized.
   Node* ExternalConstant(ExternalReference ref);
+  Node* ExternalConstant(Runtime::FunctionId function_id);
 
   Node* SmiConstant(int32_t immediate) {
     DCHECK(Smi::IsValid(immediate));
     return Constant(immediate);
   }
 
   // Creates a dummy Constant node, used to satisfy calling conventions of
   // stubs and runtime functions that do not require a context.
   Node* NoContextConstant() { return ZeroConstant(); }
 
@@ skipping 42 matching lines @@
   Node* NumberConstant(double value);
 
   DISALLOW_COPY_AND_ASSIGN(JSGraph);
 };
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8
 
 #endif